A. Field of the Invention
The present invention relates to an inkribbon feed mechanism of a printer or more particularly to the inkribbon feed mechanism which feeds the inkribbon by utilizing power of a spacing motor by which a print head is traversed.
B. Description of Prior Art
In a wire impact printer, for example, the so-called open reel system, the inkribbon is stretched between a pair of spaced reels on the left and right sides of the printer. The inkribbon is fed to a printing position between a print head and a platen. To achieve an improved printing quality, the inkribbon should be exactly fed in accordance with the movement of the print head which traverses from the left to the right side of the printing width. In addition, when the inkribbon from the supply side of the reel is exhausted, the direction of the inkribbon should be quickly reversed so that the empty reel may take up the inkribbon in the open reel system.
In the prior art, motors are provided for each reel on the left and right sides for feeding the inkribbon, or a motor exclusively for feeding the inkribbon is equipped for rotating a reel. For reversing the inkribbon, the motor is rotated in the reverse direction and contact with a gear member is changed. But, with the first scheme, the cost for production is raised because two motors are needed for feeding the inkribbon. In accordance with the latter scheme, the direction of the motor should be kept until command means, such as an eyelet appears from the reel. Moreover, the direction should be kept in memory when an electric source of the printer is turned off. For these reasons, the prior art mechanism is complex and expensive.